a. Field of the Invention
The present invention relates to a working platform lifting apparatus for an aerial ladder truck for fire fighting purposes used for operations at high altitudes, for example, for extinguishing a fire in a multistory building or for saving a person who has been left behind the scene of a fire.
B. Description of the Prior Art
Heretofore, an aerial ladder truck equipped with a working platform movable up and down along the extensible ladder has been known in the art. The conventional aerial ladder truck of this type, however, has the disadvantage that the extending and contracting operation of the ladder and the raising and lowering operation of the working platform interfere with each other. As a result, the operations and mechanisms of the ladder and working platform are very complicated. Further, in a safety aspect of the working platform, there are problems which must be solved.